Thread-trimming device for sewing-machines.



H. W. SLATER. THREAD TBIMMING DEVICE FOR SEWING MACHINES.

APPLIOATION TILED JAN.25,1907.

Patented Jan. 5, 1909.

2 SHEETS-SHEET 1.

WIYNESSES: WWM

H. SLATER. THREAD TRIMMING DEVICE FOR SEWING MACHINES. APPLICATION FILED J'AN. 25,1907.

908,619. Patented Jan. 5, 1909.

2 SHEETS-SHEET 2.

WiTNESSES:

A ATTNEYS UNITED STATES PATENT OFFICE.

HARRIS W. SLATER, OF LAKE MAHOPAO, NEW YORK, ASSIGNOR TO THE N ATION A L MhCHIN E COMPANY, OF MAMARONECK,

NEW YORK, A CORPORATION OF NEW YORK.

THREAD-TRIMMING Davies roa SEWING-MACHINES.

Specification of Letters Patent.

racemes Jan. 5,1909

. Application filed January 25, 1907. Serial No. 353,939.

$ all it may concern:

Be it known that I, HARRIS W. SLATER, a citizen of the United States of America, a'nda resident of Lake Mahopac, county of Putnam, State of New York, have invented certain new and useful Improvements in Thread-Trimming Devices for Sewing-Machines, .of which the following is a specification, reference being had to the accompanyin drawings, forming a part thereof.

lily invention relates to thread trimming devices for sewing machines, and particularly to thread trimming devices adapted for trimming the needle thread of a buttonhole sewing machine, or other machine for producing groups of stitches at predetermined points.

My invention consists in means for nipping the end of the needle thread to hold same after the group of stitches has been completed and before the removal of the work operat-' work, the act of removing the ing to sever the thread thus held, and also to sever the, thread end which may protrude means the two threads are severed from the work at the point of commencement of the group of stitches.

close to the work, while the end of the needle thread the thread trimming 3-3 of Fig. 2.

is securely held, so. that the same will not be withdrawn through the eye of the needle when the'new stitching operation is commenced.

In order that-my understood, I will describe indetail an embodiment thereof, having reference to the accompanying drawings illustrating "same, and will then point out the novel features in claims. I In the drawings: Figure 1 is an end view of a buttonhole sewing machine, with my improved thread trimming and nipping device employed in connection therewith. Fig.

2 is a top view in detail of certain parts of the machine including the work clamp. and

device which is mounted thereon. Fig. 3 is a detail sectional view through the work tion being taken substantially upon the line Fig. 4 is an end View of the work clamp and 'of the .thread trimming mechanism. Fig. 5.is a detail view hOIl zontal. section of certain'parts of 1th thread trimming and gripping mechanism. Figs.

views substantially u In the line 6-6 comprising a relatively By this.

invention may be fully star wheel clamp, the plane of sec- The said surfaces co-act showing the thread trimming and gripping device in diifereiit positions" with "relation to the part of the work clamp which supports the same. i

The sewing machine illustrated is of the buttonhole variety, comprising the usual bed plate 10 and overhanging arm 11, a laterally vibrating and vertically reciprocating needle bar 12 being mounted in the end head of the said overhanging arm '11, all as will be well understood by those skilled in the art to which this invention appertains. The work is presented for stitch ng by a work clamp stationary bottom plate 13, and a relatively movable upper member 14 pivoted to the lower plate at 15, and carryin a presser foot 16 arranged to bear upon t e Work and press same down against the lower plate 13, a spring 17 being employed toapply the proper yielding pressure to the said upper member for this purpose. Suitable feeding the medium of a feed plate 18, one end of which-appears in Fig; 2, said feed plate carrying said work clamp bodily, and itself operated by the usual or any desired mechanism. (Not shown.) V

The mechanism constituting the invention herein comprises a star wheel 19 mounted beneath a plate 20 formed as a part of the upper work clamp member; 14. The said star wheel is secured to a vertical stud 21, which is mounted to rotate in the saidplate 20, a pinion 22 being also secured to the said stud and arranged above the said plate 20. The extending arms of the star wheel,

of which there are four in the present instance, are arranged to travel between the under side of the plate 20 and the upper face, of a thread guiding member 23. 'Sa'id thread guidingmember has anoffset portion 24. which is secured against the under side movements are iIn- I parted to the work clamp-as a whole through of the plate 20 beyond the arms of the said i by means of a stud or bolt 25. Thearms of the star. wheel tween two surfaces,

the upper surface of the thread guide'23.

with the'upper and lower surfaces of the arms of the star wheel to form thread gripping means, either of the pairs of 'co-acting surfaces forming an efhem.

festive device for nipping athread betweenof Fig. 2, t

.10 19..thus pass ber 7 one the under surface p of the plate 20, as aforesaid, and the other i5 pawl mounted upon 15 oceratin lever 1 279 gagement with The star Wheel may he elven a step by step movement of rotation lay any suitable means, the means herein shown comprising a ratchet wheel a pawl '27 therefor, said operating arm 28, and a spur gear 29 in mesh with the pinion and secureol to rotate with the rat het Wheel 26. .lhe ratchet Wheel and the spur gear 529 are both mounted upon a stud 30, itself mounted to ,rotate'iu the plate 20.,

while the operatli'lg arm 28 is mounted loosely upon the saicl stud. so that. it 11. .23 have a free rotative movement with respect thereto. Pivotecl to the outei: entl the a a .lollower bar 31, saicl follower bar arran ed to have a. sliding en- Y oearing member 32. the free end of said bar being in the path of a tempo; or cam 33 car ied by rock shaft A retractilc spring 3, between the -l)11' 31 and a relatively stationary portion of the 111&Cl3l.11(,.tGfitlS to draw the bar 31 up to the cam ancl maintain the encl. of the saiol be in contact with the working axial cam. rocking; movement lmparted to the rock shaft will reciprocate the bar 81, the operating arm 28 being oscillated "here anc. step by step movement thus iianarl'ctl to the star wheel. The; rock shaft is arranged to he operated by an attend.- mt, an operating arm being provided for this purpose. The ordinary function of the said. cock shaft 334 is to lift the upper member ll of theworl clamp the completion of a o1Wooflhole cam or tappet I5? thereon being; arranged to engage. an eaten sic-n 38 of the said clamp member ll, the 'ension being on the opposite sitle of the )port 1.5, so that, by depress the sa cnsiou 38. the member 1.4- as whole is lifted The relation of the two cams or, tap-pets 53 and 37 is such that'the said cam or topper will commence to operate innnetliately the rock shaft Ill is nicweti, While the cam or tappet 3? will no. come into play until the latl'er part of the movement of the rock shaft so that the movement ini-parlecl to the operating arm 28 through the follower bar 31 will surely be completcc. when the member l l is lifted. it will he remei'i'il'iered that. the member i l is liftctl to permit the ren'ioval of the Work after the compicliou ol the stitching for a bultoiiiaolc or other group of stitches, and it. is at this time that it is required to nip the needle thrczul so to permit sc'i'crancc thercol near the Work. u'nrl to hold the thread end for a new stitching; operation. The one-ration, then. of the rock shaft 3% by the attendant upon the completion of the butlonl'iolc, will operate to give a step by step movement to the slur wheel a distance hchvccn l'WO of Us arms (in iliis case one quarter of a revolution.) The arm of the star wheel coming into play at, this time,

face of coat? eoeme moves across the path of the needle thread,

hence such arm will. carry a loop of the needle thread with it to its new position be tween the plate 20 and the thread guide .23 seel ig. of the drawings.) The thread will he gripped by the gripper in two places between the lower surface of the plate and the upper surface of the star Wheel arm, and between Wheel arm and thread guide 223. thread guide which it receives erly guide the thread with respect thereto. part-of the movement upper member 1% will he release the Work, so that the work drawn out by the attendant and re-pos1- tioned for a new sewing operation. act of drawing out the Work, however, sever the thread. This severance is accomplished by means of a stationary knife blade 39 located beneath the thread guide with its cutting eclge across the bifum catetl end thereof.

is forked at the end at During the latter of the rock shaft the lifted bodily to this cutting lmil'e, so that the movement of the WSl'lL' will readily EiEEClB the severance of the thread, as will be Well understood. A thin plate l0 is supportecl beneath the said knife lolacle 89 having a bifurcated end in register with the bifurcated end of the chreacl guide 23 to form a supplemental thread guide and to insure the proper presentation of the thread to the trimming knife for a cutting operation.

in Fig. 6 the parts are shown with the work in a position just ready for a cutting operation, thread encl which goes to the the lower surface ofthe starthe upper surface of the It Wlll. be noticeel that the the threacl, so as to prop to a central positlon co may be,

The will The thread in being nipped Wlll be presented against the face of needle being: securel h ld b the thread nin- V n i ping or gripping dBVICQ In Fig. 7 the parts are shown in their positmns following the commencement of a new sewing operation. The new end will now be seen to have been rcceiveil by the work and to extend between the work and the gripping device. The en- .ire operation of sewing a buttonholc may now take place with the thread cml still helcl in this position, as it is not necessary to relieve the same, on account of the thread nipping clcvicc being: carried by thcwork clamp, and hence being IHOYLKl with the were. When. the new group of slilches has been completed anal the slur wheel has :uzain lzecn movctl Vacarry over a new loop ol the needle thread and nip the lhrcml end, the thread entllei't at the he zii'ming of the sowing operation may he momentarily released by such movement of the star wheel, lhc free cntl being,h wever,carried over :mrl allowed to lie on top of the thread guide 23. The arm of {he starfirhccl, \vhim comes inlo play to replace th arm which has gone foramsm employing a needle thread, of an arm ingoperation, the latter threadgoin up the Removal of the work wi l severneedle. both threads quite close to the work, and, as

set forth above, will hold the needle thread" for .a new operation. Fig. 8 shows the star wheel as just moving into position to gri both thread ends, the'threadend from the commencement of the work the upper surface of the thread guide 28.

What I claim is:" 1 1. In a sewing machine, the-combination with a work clamp and stitch forming mechanism employing a needlethread, of an arm having upper and lower gripping surfaces, the said arm arranged to move laterally across the path of the needle thread and to engage and carry a loop of such thread with it, upper and lower thread gripping surfaces arranged stationary upon the work clamp with which the upper and lowersurfaces of .the said arm are adapted to co;act, both of said upper and-lower pairs of co-acting surfaces adapted to grip and hold a thread between them, and a cutter arranged to cut the thread at a point between the work, andthepoint at which the thread In a sewing maphine, with a work clamp and stitch forming niechis gripped.

arranged to move laterally across the path .of the needle thread and to engageand carry a loop of such thread with it, a stationary gripplng surface arranged beneath the said arm for co-acting therewith, and a thread trimming knife arranged beneath the'said co acting surfaces adapted to trim the thread effected held by the gripper, suchtrimming being by the act of removing the 'work from a sewing position, the said thread trimming knife being mounted stationary upon and carried by the said work clamp.

In a sewing machine, the combination with stitch forming mechanism employing a needle thread, of anarm arranged to move laterally across the path of the needle thread and to engage and carry a loop of such thread with it, upper and lower thread gripping surfaces with which the upper and lower surfaces of the said arm are adapted to co-act, both of said .upper and lower pairs of co-acting surfaces adapted to grip and hold a'thread between them, and a stationary thread trimming knife arranged beneath said surfaces adapted to trim the thread held by the gripper, such trimming being effected by the act of removing the work from a sewing position, 4. In a sewing machme, the combination the beginning of the sewing oplying free upon the combination trimming knife arranged thread gripping surfaces senting work for ried by said Work with stitch forming mechanism employing ping means for simultaneously gripping the,

free end of the thread extending from the work at the point of commencement of the sewing, and the thread extending from the work at the point of completion of the ewing, the latter said thread being the tun-ad which passes to the needle of the machine, and a' stationary thread trimming knife, arranged between the work position, whereby the act of removing the Work from its sewing position will cause the said knife to sever both the said threads.

In a sewing machine, the combination with stitch forming mechanism employing a needle thread, and a work clamp b an upper member carrying a supporting plate, of an arm pivoted immediately beneath said plate arranged to swing in a horizontal plane across the path of the needle thread, a thread guide mounted immediately beneath the said arm, the said arm adapted ping operation withthe under surface of the said plate and with the upper surface of the said thread guide, a stationary thread trimming knife carried by said work clamp immediately beneath for operating said work clamp to release the work therefrom,

and mechanism also operated by said meansfor operating the saidswinging arm.

gripping. means and the thread guide, meansto co-act for a grip- 6. in a sewing machine, the combination with stitch forming mechanism employing a,

needle thread, of a star wheel having arms arranged to move across the path; of the needle'thread, upperand-lower thread gri ping surfaces with which the arms of t 6 said star wheel are adaptedto en age, the

said upper and'lower surfaces and t 6 upper and lower surfaces of the arms of the'said star wheel-constituting two sets of gripping surfaces in diflerent planes each of which is adapted to engage and holda thread, means for imparting step by step said zstarwheel, and a stationary thread contiguous to the same, substantially as set 'forth.

In a sewingmac'hine, the combination with a} needle-thread, of a work clamp for "pre stitching, a star wheel carclamp, the arms of said star wheel arranged to co-act with a relatively stationary portion of said work clamp stitch forming mechanism employing a stationary trimming movements to the and beneath themama ments to the said 8 In a sewing with stitch form 5 a needle thread,

senting work to earriecl by said said star wheel relatively station 10 clamp to form a a thread guide mounted beneath movement of sai arranged to (3 star wheel.

machine, the Combination ing mechanism of .a Work clamp 1- stitching, a Work clamp, the

any portion 0 pair of gripping th d star Wheel, sai

employing for pre star Wheel arms of o-act with a t said Work surfaces. e path of (1 thread arms forming a second.

ces, a stat onary trimbeneath said thread guide and star Wheel pair of gripping surta ming knife mounted guide, means for operating said were clamp to release the Work held thereby and mechanism operated by the same means which so operates the Work clamp for imparting step by step movements to the star wheel.

. HARRIS N. SLATER.

' Witnesses:-

D. HOWARD l-li=vin on,' LYMAN S. ANDREWS, Jr. 

